The primary goal of this research is to develop a macaque monkey model for complex-partial seizures during the first year of life. The research is important because an estimated 3-5% of children in the United States have at least one seizure before the age of three. There is concern that early seizures may adversely affect cognitive and emotional functioning during childhood. Cranial assemblies are implanted on project animals using stereotaxic surgical techniques. In previous years we attempted to induce seizures by the microinfusion of bicuculline methiodide into an area deep within the piriform cortex. Unfortunately this procedure was not reliable in obtaining seizures on a regular basis. Therefore, we tried two other protocols. First, in four animals we attempted to induce seizures by the infusion of drug into the hippocampus. Again, the results were inconsistent. Second, in another four animals, we induced seizures by infusing drug into the entorhinal cortex. The latter procedure was very successful, and we were able to obtain seizures in every animal on our first attempt. Follow-up studies indicated that a single prolonged seizure produced brain changes that were apparent on high-resolution MRI scans, and these changes were verified by histological examination. Our work over the past year has resulted in the first infant primate model of complex-partial seizures. FUNDING NIH grants RR00166 and MH01201. Gunderson, V.M., Gale, K.N., Dubach, M., Schwartzkroin, P.A., Born, D.E., and Wenzel, J. Seizures in young monkeys are associated with long-term behavioral deficits. Epilepsia 39 (Suppl. 6) 237, 1998. Born, D.E., Wenzel, H.J., Gunderson, V.M., Szot, P., Dubach, M.F., and Maravilla, K.R. Intrahippocampal bicuculline-induced seizures in young primates produce mesial temporal sclerosis. Epilepsia 39 (Suppl. 6) 134, 1998.